reset problems with Gen7 1.5

hi there,

we have built a gen7 1.5 (atmega 1284P @20 Mhz) for testing purposes.

the board seems to work ok (we have made few prints with it), but we have some problems:

1. we have to press the manual reset button each time when we try to load the marlin firmware. We connect to gen7 with a usb cable. As far as I have understood the reset is required only for usb-ttl cables. But why we need to press reset also with a usb cable ?

2. we have to press the reset button when we connect to the board with repetier. This is required only when the board is powered-up for the first time.

I have checked with the MCP2200 utility and the CTS/RTS is disabled.

any ideas are welcomed.


thank you,
mihai

Apparently, auto-reset isn't working. It's a feature which hijacks the hardware handshaking lines to use it as a reset signal.

The unfortunate thing is, the signal is logical 1 with no serial line connected, too. So you see only a very short drop in voltage when connecting with a serial terminal (or Pronterface or whatever).



The red oval shows the bridge which runs the reset line. On my Gen7 the voltage drops from 5.09V to 5.06V for a second on a cheap voltage meter. Also, it's worth re-checking the solder joints in this area.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY